这一篇主要介绍在window下添加新对象，网上也有一些文章介绍如何添加，文章有些老了，我试了好多次才成功，这里记录下来用于备忘。

一、Source/WebCore/page下添加新文件

1. HorkyWebObject.h

#ifndef Horky_WebObject_h
#define Horky_WebObject_h

#include "DOMWindowProperty.h"
#include "ScriptWrappable.h"

#include <wtf/Forward.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>

#include <wtf/text/WTFString.h>

namespace WebCore {

class HorkyWebObject : public ScriptWrappable,
                       public RefCounted<HorkyWebObject>,
                       public DOMWindowProperty {
   public:
    static PassRefPtr<HorkyWebObject> create(Frame* frame) {
        return adoptRef(new HorkyWebObject(frame));
    }

    String description() const;

    //~HorkyWebObject();

   private:
    HorkyWebObject(Frame* frame);
};

}  // namespace WebCore

#endif  // Horky_WebObject_h

2. HorkyWebObject.cpp

#include "config.h"

#include "HorkyWebObject.h"

namespace WebCore {

HorkyWebObject::HorkyWebObject(Frame* frame): DOMWindowProperty(frame) {
    // construction
}

// HorkyWebObject::~HorkyWebObject() {
//     // destruction
// }

String HorkyWebObject::description() const {
    return "Hello World!";
}

}  // namespace WebCore

3. HorkyWebObject.idl

interface HorkyWebObject {
    readonly attribute DOMString description;
};

这里主要参考了网上的文章，但是这里的坑点是需要继承DOMWindowProperty，具体为什么可以参考通过idl文件生成的JSC binding，里面有用到vtable。

二、修改DOMWindow

1. DOMWindow.h

public:
    ...
    HorkyWebObject* horkyWebObject() const;
    ...

private:
    ...
    mutable RefPtr<HorkyWebObject> m_horkyWebObject;
    ...

2. DOMWindow.cpp

void DOMWindow::resetDOMWindowProperties() {
     ...
     m_sessionStorage = 0;
     m_localStorage = 0;
     m_applicationCache = 0;
+    m_horkyWebObject = 0;
 }

HorkyWebObject* DOMWindow::horkyWebObject()const
{
    if (!m_horkyWebObject)
       m_horkyWebObject = HorkyWebObject::create(m_frame);
    return m_horkyWebObject.get();
}

3. DOMWindow.idl

 [Replaceable] attribute HorkyWebObject horkyWebObject;

三、修改编译文件

1. 修改Source/WebCore/DerivedSources.cpp

 #include "JSNavigator.cpp"
+#include "JSHorkyWebObject.cpp"
 #include "JSNode.cpp"

注意前面的+号。

2. Source/WebCore/DerivedSources.pri

  $$PWD/page/Navigator.idl \
+ $$PWD/page/HorkyWebObject.idl \
  $$PWD/page/Performance.idl \

3. /Source/WebCore/Target.pri

  page/Navigator.cpp \
+ page/HorkyWebObject.cpp \
  page/NavigatorBase.cpp \

注意这里（Phantomjs）编译使用的是qmake和make，所以修改的qt工程文件；如果使用cmake编译的话需要修改相应的cmake文件。